Testing Angular component with unsubscribe Error during cleanup of component

Question

I\'m testing a component which subscribe router params. Every test pass and everything works fine. But if I look in the console, I can see an error:

Error

Answer 1

The "Error during component cleanup" error message happens because when ngOnDestroy() is called, this.routeSubscription is undefined. This happens because ngOnInit() was never invoked, meaning that you never subscribed to the route. As described in the Angular testing tutorial, the component isn't initialized fully until you call fixture.detectChanges() the first time.

Therefore, the correct solution is to add fixture.detectChanges() to your beforeEach() block right after the createComponent is called. It can be added any time after you create the fixture. Doing so will ensure that the component is fully initialized, that way component cleanup will also behave as expected.